OJ287 was first detected as a radio source in
the Ohio surveys in
1968.
It was soon identified with a 15thmagnitude compact blue object like a typical quasar.
Unlike a normal quasar, the optical spectrum
was found to be
featureless, but very weak, variable emission lines have since been detected, with a red shift of
z=0.306.
OJ287 was classified first as a BL Lac Object
and, later, as a
blazar – a quasar with extreme variability.